


All Hail The Bellabooty!

by NutJob



Category: RWBY
Genre: Ass Expansion, Bellabooty, F/F, Futa, Futanari, Futanari Yang Xiao Long, Magic Potions, butt growth, cock growth, sexual awakening, slight mental corruption
Language: English
Status: Completed
Published: 2021-01-31
Updated: 2021-01-31
Packaged: 2021-03-18 01:00:13
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,594
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29109693
Author URL: https://archiveofourown.org/users/NutJob/pseuds/NutJob
Summary: It's April Fool's Day so you know what that means.Yang is going to subject her partner to an oddly sexual prank. Nothing can go wrong. Nothing...Everyone is 18 years old and over.Butt expansion, Futanari, cock growth, slight mental corruption/ sexual awakening
Relationships: Blake Belladonna/Yang Xiao Long
Kudos: 30





	All Hail The Bellabooty!

**Author's Note:**

> Repost from HF Enjoy!

Tomorrow was April fool’s day. Yang’s favourite day of the year, well other than Christmas, her birthday and the last day of the school year. 

However what those days didn’t have was a get out clause of any prank she pulled. Now Yang was not a cruel prankster like Cardin or his lackies, no she had an artform. Find something interesting or weird about someone and dial it up to 11, normally in a sexual manner. Like last year finding out that Weiss had a crush on the new professor, Professor Copper, Yang had a large copper statue of the man made for her, with an over exaggerated bulge on the front. 

Or the year before when Ruby confessed she was gay as David Bowie, and while Yang loved her and supported her, she did however, over the course of the sacred 24 hours, convince the poor girl that she had a secret admirer in the year above them, with some fake nudes included. 

Both relatively harmless pranks that Yang made sure that at any point she had the ability to stop them before that got out of hand or someone’s feelings were hurt. Yang did love her team and didn’t want to mess with them too bad. 

But now that brings us back to today with it being Blake Belladonna’s time in the limelight. Yang had been trying to think all year of a prank to do but everything was too easy or too mean. From messing with her precious smut book collection to using her Faunus traits to put her in an embarrassing situation. Yang just couldn't think of anything. 

That was until a very drunk and very very stupid Jaune was dared to rate all his friends’ asses by an equally drunk Pyrrha, the girl obviously trying to get a complement out of her boyfriend, only for the moron the rate a certain cat Faunus above her. 

So it began, Yang’s plan started to form. With her target and theme set all she had to do was decide what to actually do. She went through so many half baked ideas, pieces of paper littered the floor of her dorm as she schemed and planned. 

However an idea struck Yang, Blake being quiet and a private person, hated drawing attention to herself, if her ‘Bellabooty’ couldn’t help but do that it could be kinda funny, if done right. 

Yang did some research on ways to get this effect and sure enough she found a Dust potion shop just recently opened in Vale. Prefect. 

With that the busty blonde hopped onto her motorcycle Bumblebee and drove into town. 

Yang pulled up outside the small, old shop that was tucked behind a row of other much larger shops. Far removed from the busy highstreet it became eerily quiet. The shop itself looked old and abandoned, made of fading brick and crumbling mortar. A dark green sign above the window with the words Eve Of The Eclipse written in black writing was the only indication that this was even a shop. Or occupied at all for that matter. 

Yang stepped into the building and she called out, “Hello!? Is anyone there?!” 

“Yes! I’ll be there in just a moment dear!” Came a voice from the back of the shop. As Yang’s eyes adjusted to the dark cool room she saw piles of old dusty books lining rows and rows of wooden shelves. A few candles, burning a creepy green flame, dotted around the shop, provided little light. But what Yang found odd was there were no actual potions in sight. Just more books and other odd nick knacks. 

“Why hello, my what a beautiful young lady!” This robed woman said, seemingly appearing next to Yang.

“Ahh!” Yang jumped back in response to the close proximity to this mysterious woman. But now that Yang had a chance to look at her, she realised how hot this woman was. 

Her face, a warm chocolate brown in colour, looked flawless. She had a cute button nose, visible cheekbones and these vivid purple eyes that swirled hypnotically. Her whole body was draped in a burning red robe with a golden leaf, highlighting the woman’s voluptuous figure. The robes, seemingly far too tight, clung to her wide hips and showed off her juicy thighs. They hugged her tiny waist only to stretch outward to hold in her mind boggling breasts. Yang being a naturally endowed girl had never felt this way. A wave of envy washed over her as she stared at the gravity defying tits. Even as the woman breathed they swayed, just calling for her to enjoy them, to stick her face in the massive canyon of visible flesh that her cleavage provided. 

“Ahem,” The woman cleared her throat, snapping Yang back to reality, looking up at the woman she wore a smug smirk on her face. “Would you like to buy anything or just stare at my tits all day?” 

“Argh? I..I..I’m sorry I didn’t mean to stare,” Yang uncharacteristically blushed. 

“Haha, no need to feel ashamed around me child I was once like you, back in my day.” She turned around and started walking to the counter at the far end of the shop, her large round ass swaying back and forth for Yang to enjoy, “What can Madame Eve do for such a beautiful young woman?” 

Yang lost in Eve’s jiggling ass, struggled to remember what she came for until they reached the counter and that heavenly butt disappeared round the counter. 

“Argh sorry I came here for a potion.” Yang once again snapped alert, trying to maintain eye contact this Madame Eve.   
“Well yes I could guess that, I do run and own a potion shop darling.” Eve rested her elbows onto the counter, revealing even more cleavage to the younger woman. “But what sort?” 

“Oh right, well this is going to sound weird.” 

“Try me~” Eve smiled seductively, she couldn’t help it. Teasing this sexy school it just got her motor running. 

“I need a potion to well… enhance someone else’s…” Yang stopped, trying to form the words, knowing how crazy they sounded.

“Someone else’s…” Eve motioned her to continue. 

“Butt!” Yang unintentionally blurted out.

“Ahh, I see, can I ask why?”

“For April Fools of course.” 

Eve chuckled at this, “Ah is it that time of year already, well then shall we get started?” Yang nodded. 

Eve lifted a large black pot onto the counter, already filled with a boiling bubbling black liquid. She began to pull out various jars of Dust mixing them in at blinding speed. Yang to start with, tried to keep up with what she put in but soon got lost in Eve’s giant breasts once again, they jiggled and heavied as she moved around adding more and more ingredients. Finally Eve reached into said cleavage and pulled out a small cloth pouch, reaching in, she held a pink Dust crystal and held it into front of Yang, “Say the name of the person you want this potion to effect.”

“Blake Belladonna.”

With that Eve threw in the pink crystal, turning the mixture a violent red and she started to chant, “YOOTBALLEB WORG!” Flash! A great big puff of smoke rose from the pot. Eve reached under the counter on final time, pulled out a angular glass flask and dunked it into the liquid, filling it before handing it to Yang. 

“Pour this onto her panties and the desired reaction will happen.” Eve smiled. 

“Thanks, Is there a way to stop the reaction if things get too out of hand?” Yang tucked the potion away in her bag.

“Of course just merrily drink the potion and the effect will fade so make sure to leave some.” Eve warned.   
“Thank Madame Eve how much do I owe you,” Yang held up her wallet as a sign she was ready to pay.

“Haha don’t worry about payment this time my dear Yang consider this a gift to a girl that reminds me of myself.” 

“Ready are you sure?” Eve nodded a confirmation, “Thank you so much if you need anything just get in touch.”

“Oh trust me I will Yang, I will.” Eve grinned with a slightly darker expression. 

“Ok bye!” Yang raced out the shop, ready to set her plan into action.

Once the young woman had left, Eve groaned loudly, her robes distorted as a huge two foot long cock sprang out from them. “I thought that bimbo would never leave!” Eve moaned as she stroked her cock to the fresh memories of Yang eyeing her up. “Well let’s see how long it takes her to return~”

Yang arrived home late, with the setting sun warming her back as she entered her dorms. Once outside her team’s door she listened in to hear who was in there. Her sister Ruby could be heard singing in the shower and Weiss complaining about her poor tune. Opening the door she saw that Blake was nowhere to be seen. 

“Where is Blake?”

“She went out for a run. She’ll be back soon, why do you have a moronic prank to pull?” Weiss crossed her arms, unamused. 

“The prank isn’t until tomorrow Ice Queen and besides she helped me with your prank.” Yang smirked, knowing that would win the Schnee to her side. Or that the very least stop her telling Blake anything she saw. 

“Hm! I knew as much. Well I hope you get her good, just don’t expect me to rescue you if it goes wrong.” Weiss huffed, climbing into bed. 

“Duly noted,” Yang smiled smugly knowing her trick had paid off. Walking over to Blake’s dresser she opened the prized pantie draw and splashed all of them with the potion, making sure to leave enough to reverse the effect after she had her fun. 

“What was that?” Weiss questioned, “It better not be itching powder.”

“What no of course not, just something to spice up Blake’s day tomorrow, nothing too major.” Yang said, trying to keep Weiss calm. 

Weiss just rolled her eyes, and wrapped her covers over herself, ready to sleep. 

Yang quickly followed suit once she was certain the potion had set. Feeling giddy as she tried to fall asleep she couldn’t help but giggle to herself as she heard Blake enter the room. 

“What are you giggling at Yang?” Blake asked cautiously. She was well aware that tomorrow would likely test her friendship with the blonde. “If you have any plans for tomorrow you may as well change them Yang.” Blake walked over to her dresser and began change into her pajamas. 

Yang moved onto her side, arm propping her head up, “And why is that my feline friend?” 

“Because I plan to hide in the library for exactly 24 hours so you can’t set any demented prank into action.” Blake pulled off her shirt and bra, her perky C cup boobs bouncing, now free from their confides. 

“Well what if you need to go to the bathroom?” Yang quizzed, playing along while knowing full well it didn’t matter what Blake did, so long as she put a fresh pair of underwear on.

“I have special permission from the librarian to use her personal bathroom in her office.” Blake unbuttoned her white shorts and pulled them down. Yang drooled slightly as she saw her target completely visible, bar the thin pair of blake tights that seemed to only highlight the gorgeous round booty. It was firm, sticking out a good few inches behind the Faunus, but jiggling hypnoticly as she pulled up her pyjama shorts. The two orbs of juicy flesh looked perfect to squeeze and spank. Yang continued to stare at Blake's bellabooty as she walked into the bathroom to brush her teeth. The way it moved with this teasing sway as Blake went about her business.

Wiggling down her bed to sleep Yang grinned with glee, excited for the perverted shenanigans tomorrow would bring. 

Chapter 2.

*BEEP* *BEEP* *BE-SLAM*   
Yang unclenched her fist and stretched her whole body. “Today is the day,” she mummed to herself gleefully. 

Leaning over the side of the bed seeing that Blake was indeed gone like she said she would be, Yang rubbed her hands together in sadistic joy, knowing that her plan was already in motion. Hopping out of bed, she continued to stretch and began her morning routine, wondering how Blake was doing. 

Blake sipped her black coffee as she peacefully studied the Grimmology textbook in front of her. The sound of falling books elsewhere in the room made her jump, spilling the precious liquid down herself. She spun her head around expecting to see a certain busty blonde with itching powder or something just as cruel. Instead she saw a terribly red Pyrrha blushing as she scrambled to pick up the shelf load of books that just fell. 

‘I’m actually very surprised Yang hasn’t tried to prank me yet,’ Blake thought to herself as she got up to go to the private bathroom to clean up, ‘Maybe I should be thankful but I can’t help but feel… worried. Like she has already got me and I just haven’t noticed yet.’ 

As she walked from one end of the room to the over, she couldn’t help but notice her weight shifting around more, especially around her behind, looking down she didn’t notice anything wrong, other than the coffee stains. However Pyrrha and the rest of the room did notice. As Blake moved the sway of her hips grew wider and the orbs of assflesh grew thicker and bouncier. The noise of fabric straining slowly grew with each second as Blake’s thighs also got juicer. 

Pyrrha craned her head around the other onlookers in awe. Even to her it was… magnificent. The teasing nature in which it swayed so hypnotically, the light bounce of each cheek as they rubbed together.

The bathroom door closed on an oblivious Blake and her godly derriere the whole room snapped back to life, “I need to find Jaune,” an aroused Pyrrha declared to herself as she ran out the library. 

Yang walked around the room brushing her hair, fresh out the shower, the wild beast threatening to eat her brush. Finally giving up the fight she set aside the brush only to catch a whiff of a particular smell, sweet and rich, yet salty. Following the smell around the room she eventually found the source. The Dust potion. The cap had come loose slightly, “but it didn’t smell at all last night,” Yang pondered, indulging in smelling the potion again. The scent was relaxing, calming even. Yang sat down with the bottle in hand and continued to enjoy its perfume. ‘I just have to make sure not to get any on me and I’ll be fine, Yang thought to herself as she brought it up for another whiff...

Once the coffee had been cleaned up, Blake walked out of the bathroom, returning to her seat. As she sat down she noticed two things. 1. How much higher she was sitting and 2. How good it felt. As her panties started to get damp from the sensations he subconsciously began to shift her weight back and forth, Looking down, she finally noticed how much her ass had grown, the flesh swallowing the seat entirely. Her hands reacted before her brain did, reaching behind and grabbing two huge handfuls of her now huge ass. The reaction was instantaneous. Pleasure overloaded her system like she had never felt before. Her pussy twitched she came, soaking her panties and leaving a damp patch on her shorts. 

“Holy crap,” she whispered to herself, “What the hell is happening?” Before she could even think her vision blurred, she felt her ass begin to pulse and as it did it started to grow. The pleasure returned tenfold. Blake’s tongue rolled out her mouth, as her ass grew, the feeling of it stretching her shorts and tights was incredible causing Blake to moan loudly she noticed her lewd performance had caused everyone to stare at her. This only seemed to intensify the pleasure and Blake grinned in response enjoying this new feeling without a care in the world. 

But as quickly as it came, the pleasure faded and the growth stopped. Blake, panting, stood up and admired her new asset. Her hips wider then her shoulders, her thighs thick yet defined and her ass was massive. It stood out several inches behind her and in her already too tight shorts she could make out every detail of each glorious watermelon sized orb. 

A single thought entered her head at that moment, ‘Yang’. “I guess I should go punish her,” Blake smirked, “Or reward her I haven’t decided yet.” With that she walked about the stunned library, where not a soul dared move, too afraid to ask any questions or start a conversation. 

Yang who by this point was solely focused on enjoying the smell of the potion suddenly felt very faint. Pulling herself out of her aurora based day dream, she noted her vision grow darker, before she could even call for help her mind went blank and she fell to the floor in a heap, the still open potion vial slowly rolling around the floor, causing small amounts of the potion to spill onto Yang. 

As Blake walked through the halls at Beacon, for the first time in her life, reveled in the attention she was receiving. Walking down the centre of the hallway, a smug smile on her face. She purposely swayed her fat ass around more to attach more eyes to it, and it felt amazing. Her pussy juices once again started to flow down her legs as this continued. She loved the feelings her huge ass gave her, The sensation as the weight of each cheek shifted, lightly clapping them. The heat that the rubbing of her thighs made teasing her quivering pussy further. The bounce that her bubble butt did as she took long confident strides. It was amazing and she didn’t want to give it up. At least not until she had some fun with it first. 

Arriving at team RWBY’s dorm room door, Blake braced herself for Yang’s reaction, because while she had growth to enjoy her new ass and the pleasure that came with it, she knew Yang was behind this and would most definitely see the funny side of it. Opening the door, Blake saw an unconscious Yang on the floor with some weird looking vial next to her. Dread rushed through her head as Blake ran to her side. Kneeling down and resting Yang’s still head on her soft thighs. “Yang!” Blake exclaimed. “Wake up!” Blake looked around the room hoping that either Weiss or Ruby would just appear to no avail, she knew full well they both had double Dust chemistry and wouldn’t be back till the end of the day. 

The sound of Yang stirring shook Blake out of her thoughts. “Arghhh... what happened?” Yang groaned, bringing her hand up to her head in pain, “My head is pounding.” 

“Yang!” Blake hugged the girl tightly. 

“Oh hey Belladonna,” Yang then saw Blake’s thick ass protruding behind her and smirked, “Or should I say Bellabooty?” 

*SLAP* “God damn it Yang!” Blake shrieked as she pushed Yang off her with a thud. “What is all this about? A prank?!” 

Blake stood up and turned her back to Yang. Giving Yang several eyefuls of her handiwork. Even with Blake now standing still those fat orbs jiggled. “Wow.” 

“Wow!?” Blake spun around “Is that all you have to say?!” 

“Blake I’m so sorry I didn’t mean for it to get that big, ok maybe that was a lie but holy crap I…” 

“That’s not what I was talking about!” Blake silenced her. “You were unconscious you idiot!” 

Blake kneeled back down next to Yang and said much more softly, “Are you ok though?” 

“Yeahh I’m fine I think, I just sniffed the potion I used on you for the prank and then.. Oooh!” Yang all of a sudden went red in the face as her eyes went cross-eyed. Ecstasy raced through her veins, her body twitched and she moaned as she felt orgasm after orgasm.   
Blake however saw something happening. A bulge was beginning to form in Yang’s black short shorts. Stretching from her crotch and snaking down her shorts finally ending with a thick pulsing red bellend poking out at the bottom of her left leg. Even though the majority of this new appendage was covered Blake could still make out every detail of it. The thick outline of every vein as it throbbed with Yang’s twitching, the fat heavy balls that Blake only just noticed stretching out Yang’s shorts. She bit her lip as lewd thoughts floated around in her head. It looked massive. Easily 9 inches. Blake’s pussy grew wet at the possibility of what kind of pleasure that huge thing could give to her already sensitive ass. 

“Yes! Yes! Yes! Ahhh!” Yang let out her loudest moan yet and finally a jet of thick white cum streamed out of the cock with one final throb. The creamy white liquid splashed onto the carpet and onto Blake’s leg, as it continued to flow out from Yang. Blake began to drool at the sight as the salty smell bombarded her Faunus senses, teasing her, edging her closer to cumming, just from the smell and sight alone. she was already horny before this, now she was in overdrive. Her hand slowly reached down, she scooped up a small dollop from off her leg on the tips of her fingers and just as slowly put her fingers into her mouth. The taste was like nothing she had ever had before. It was amazing and she wanted more~.

Panting hard as her first male orgasm died down Yang had a chance to regain her senses. Sitting up she said “Wow that was something huh Bl-” A swift hand pushed her back into the ground. Blake saddled on top of her, Yang could feel the heat and wetness from her snitch through her clothes. Blake looked into her eyes with a feral glare. “Yang I am going to ride this huge piece of cock till I am satisfied. Understand?” 

“Okayy sure just let me-” Rip! Yang’s shorts, torn with one hand, were thrown across the room followed by a second rip as Blake tore her own white shorts off and shifted her panties out the way of her soak trimmed pussy. 

“Just be quiet and let me enjoy this,” Blake demanded as she lined up Yang’s cock with her pussy. Then dropped. Hard. 

Instantly Yang’s seemed to find Blake’s G spot deep inside her. The feeling of this beast of a dick stretching out her folds was ecstatic. The way it throbbed and probed deeper inside of her. Blake shaked as a powerful orgasm raced through her. The first of many. Slowly lifting up her wide hips, she began to bounce up and down Yang’s huge dick, causing her ass cheeks to clap together loudly, seemingly every thrust she came. “Oh yeahh this is fucking amazing!” Blake moaned as her eyes rolled back and her tongue dangled out. 

Yang however was lost in a haze of pleasure. Blake’s pussy was rubbing and squeezing her dick in such the perfect way she was just trying not to cum. But her hands had other plans. They reached out and spanked Blake’s new fat ass hard before starting to kneed the two mouth watering orbs of flesh around. Something Blake apparently enjoyed. “Oh god Yang yes! More!” Even reaching down to spank her own cheeks. Yang grinned. If she wanted more she would give it. 

Yang unleashed her superior strength pushing herself off the ground whilst still deeply embedded in Blake and walked over to the bed while Blake rammed herself on Yang’s cock. Throwing Blake down onto her bed on her back, who was grinning like a mad woman. Yang began to thrust in earnest. Slamming her hips into Blake’s, the sound of Yang’s juicy balls slapping against Blake’s fatter ass filled the room. All the while Blake got louder and louder. 

“Fuck me harder you animal! Drive that huge fat cock deeper!” She screamed as she wrapped her long sexy legs around Yang’s back and then dragged Yang closer. “More!” She then grabbed Yang’s collar and their lips crashed into each other. The kiss was not a lovely or kind one, it was one made solely out of fervent lust. 

“God you are so sexy,” Yang panted as she flipped Blake over, her booty jiggling from the sudden movement, she thrusted back into Blake doggy style. “Seeing this slutty fucking ass shake and bounce on my big dick while you moan and scream like a whore.” Yang spanked Blake, leaving a large red hand mark on her white flesh. “Gotta love it. Don’t you?” 

“Your huge cock is driving me insane stop talking and fuck me harder you stud!” Was all Blake could bring herself to say, too lust crazed to think of anything else, instead putting her energy into twerking her fat ass on Yang’s dick. She could feel her limit being reached. With one final thrust from Yang, the biggest orgasm Blake had felt had raced through her. Her mind went blank as the pleasure shorted out her brain. 

Collapsing onto the bed she panted, still feeling Yang now hotdogging her ass as she laid there. Even that felt great. The still hard meat rubbing her asscheeks tingled her soul. “I’m gonna cum!” Yang exclaimed. Blake spun around and wrapped her lips around Yang’s cock just as the first blast of cum shot into her mouth. Blake swallowed and swallowed but more of the delicious cum kept shooting into her mouth, the rich creamy flavour satisfied her hunger like nothing else ever had. 

Collapsing next to her, a sweating Yang breathed heavily, “Well… that was something.”

“Yeahh it was…” Blake blushed, the rush of lust allowing her mind to return to normal. “So you made my butt grow?” 

“Arghhh yeahh I did, sorry I guess.”

“Don’t be,” Blake grinned, “When everyone was staring at me as I walked here with this thing was the best I’ve ever felt.”

“Really?” Yang looked at her confused, “Thought you would have hated it.”

“In truth, had you told me about today before it happened I would have agreed with you but after feeling the growth and the stares and this~”Blake squeezed Yang’s now soft cock, “I don’t want to lose this.” 

“Fair enough, I’m not sure about this cock though.” 

“I think you know my opinion~” Blake smiled. 

“Easy girl its a sensitive beast,” Yang winked. 

“Well I best take good care of it then~”

“Fine it can stay, besides we can both get back to normal by drinking the potion.”

“How does that work exactly?” 

“No idea but I couldn’t care less right now.” Yang yawned and stretched out on the bed and closing her eyes, “I need a nap after that.” 

“Yeahh me too,” Blake said as she got comfortable next to the blonde, resting on her side she saw the potion vial in question, somehow still containing a large amount of its liquid despite rolling around on the floor. Blake laid there and couldn’t but wonder what her butt would like if it was just a little bit bigger. ‘Only a little bit bigger’ she thought to herself, ‘For now~’


End file.
